Support Unix Domain Sockets for Postgres

[mehcode]

//cc @xcthulhu

[bikeshedder]

I just wanted to take sqlx for a test ride and found this feature missing. Is there any chance for a release including this feature soon? I almost exclusively use databases with UDS.

[dcardamo]

Likewise I would like this feature too. On GCP Cloud Run you can only connect to postgres using their cloud sql proxy which provides a UDS method:
https://cloud.google.com/sql/docs/postgres/connect-run

[mehcode]

We'll get a patch release out in the next couple days. A couple things that landed on master require a bit of testing before we can push a build out.

[dylanjt]

@mehcode I am also attempting to deploy my app to GCP Cloud Run and hitting a roadblock trying to connect via UDS.

[mehcode]

@dylanjt 0.3.5 should support UDS. What issue are you having?

[dcardamo]

Its been a few weeks since I've looked at it. I couldn't find an URL format that it would allow connecting with last time and couldn't find anything documented in the sqlx repo.

I read through the code such as sqlx-core/src/url.rs where there are some tests for connecting but none UDS. Also read through sqlx-core/src/postgres/connection.rs and there are some good comments there but none applicable to UDS.

My plan was to look into this again when 0.4.0 came out since I saw there were some changes in master that may improve this. I remember seeing some API where you can skip an URL and just provide the various field values for the connection.

It would be awesome if it were documented or there was a test case for UDS. Also very possible I missed it.

Once this works I'd be happy to add documentation on how to get this working in GCP cloud run.

[mehcode]

Its been a few weeks since I've looked at it. I couldn't find an URL format that it would allow connecting with last time and couldn't find anything documented in the sqlx repo.

Sorry for the lack of docs on it. It's actually just as specified in libpq (or it should be).

See: https://www.postgresql.org/docs/9.3/libpq-connect.html#AEN39692

postgresql://%2Fvar%2Flib%2Fpostgresql/dbname

Definitely not pretty though. You're correct. On master we have PgConnectOptions that is a builder for a connection that has a simple .socket("/var/lib/postgresql") which will have it use UDS.

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It's a bit complicated to test this in CI. I haven't had the time to figure it out.

[bikeshedder]

I personally prefer the key word syntax as it doesn't need any %2F escaping and looks way more sane:

postgresql:///dbname?host=/run/postgresql

Btw. two major linux distributions (Ubuntu and Fedora) nowadays put the UDS under /run/postgresql instead of /tmp. I've never seen the socket under /var/lib/postgresql to be honest.